In the field of information communications, conventional line aggregating techniques are used to connect between network apparatuses such as two LAN (Local Area Network) switches or the like, or between a terminal such as a server and a network apparatus. Such line aggregating techniques use a plurality of physical lines for the purpose of connecting between the network apparatuses or between the terminal and the network apparatus to improve availability.
One line aggregating technique, known as “link aggregation” is described in an IEEE (Institute of Electrical and Electronics Engineers) 802.3ad draft publication, for example.
In an example link aggregation system, a plurality of LAN lines (e.g., Ethernet or the like) connect between two LAN switches. Packets transmitted from LAN switches to LAN lines respectively are load-distributed in accordance with an algorithm such as a round robin algorithm and transmitted onto their corresponding LAN lines different from one another.
Now consider where a failure or trouble such as a line break occurs in any of aggregated LAN lines. In this case, a LAN switch is changed over so that a packet to be originally transmitted to a LAN line in which the failure has occurred, is transmitted through the use of the remaining LAN lines without the transmission of the packet to the LAN line with the failure developed therein, thereby allowing communications to continue.
While certain perceived advantages exist, the availability of communication lines between the two LAN switches can be improved.
Thus, what is needed are techniques for improved availability of a network system constructed using network apparatuses or terminals.